For messaging apps, figuring out ways to make money is a challenging task – especially when they have to do so without getting in the way of people communicating with each other. While Asian apps already make money by offering mobile games to their users, they are also experimenting with various forms of ads.

Last month, WeChat, a popular messaging app developed by Chinese Internet giant Tencent Holdings, launched a new service in mainland China that allows companies using the app to place ads on other companies’ WeChat accounts. For example, a wristwatch brand may place its ad on a clothing brand’s WeChat account; the ad is viewed by people who follow the clothing brand’s account. The fees are shared by Tencent and the companies that host the ads on their pages. Tencent, whose WeChat app has about 400 million active users, is a minority shareholder in Snapchat.

Other Asian apps allow businesses to send promotional messages.Line, developed by a Japanese subsidiary of Korean Internet firm Naver, collects fees from companies that open official accounts. The companies can send a limited number of messages to their followers each month. Kakao Talk, a Korean app developed by a local startup and minority-owned by Tencent, also offers a similar service for companies that open their own accounts.

In Asia, where standard text messages can be costly, messaging apps have become mainstream mobile communication tools. Popular apps like WeChat and Line are playing some of the roles that Facebook and Twitter have played. People use messaging apps to share updates and photos, while businesses use messaging apps for marketing.

Silicon Valley’s WhatsApp, which Facebook has agreed to buy for $19 billion, has so far kept its service ad-free. Instead, the company claims that it charges 99 cents a year after one year of free use. Still, analysts say WhatsApp’s revenue is tiny compared to Asian apps. Last year, WhatsApp’s estimated revenue was $20 million, while Line generated more than $500 million. Mobile games were the biggest source of Line’s revenue, while virtual stickers and monthly fees for corporate Line accounts also contributed.